Among the children of Israel the search for God had ceased to be blind. The promise of a Redeemer given to Adam and Eve after the Fall (Gen 3:15) became more concrete in Abraham, through whom God  promised that "all nations would be blessed" (Gen 12:1-3).

¹ Now the Lord said to Abram, Go from your country and your kindred and your father’s house to the land that I will show you. ² And I will make of you a great nation, and I will bless you, and make your name great, so that you will be a blessing. ³ I will bless those who bless you, and him who curses you I will curse; and by you all the families of the earth shall bless themselves.

This promise was renewed with Isaac and Jacob, who renamed Israel by God became the Father of the twelve tribes of Israel (Gen. 35:10). 

God said to him: "You whose name is Jacob shall no longer be called Jacob, but Israel shall be your name." Thus he was named Israel.

Among the Israelites God elected Moses to receive the Torah (Law or Teaching). By means of the Law God revealed the nature of the Justice owed to God (Commandments 1 to 3) and to man (Commandments 4-10). Fulfillment of the Law satisfies the requirements for man to be authentically human, both in relation to God and to other human beings. The man who kept the Law would be living the demands of truth as Adam had done in the garden of Eden before the fall. This Law, St. Paul tells us in Romans, was incapable of perfect fulfillment without the grace which would come through Jesus Christ (John 1:17). Its served to teach the inadequacy of the human heart, to reveal its sinfulness, rather to redeem (Gal. 3:24-25).

²⁴Consequently, the law was our disciplinarian for Christ, that we might be justified by faith. ²⁵But now that faith has come, we are no longer under a disciplinarian. 

Through the prophets, as the liturgy says, we were taught to hope for salvation. Thus the entire Old Testament was a divinely revealed preparation for the Incarnation of the Word.

The Word when He does come gives what neither Gentile or Jew had been able to give. Out of the perfection of his humanity He returned to the Father "love for love." Christ’s perfect living for the Will of the Father is both the perfection of man and the glory of God. In Christ and by His grace man becomes both fully alive and the glory of God (St. Irenaeus).